After some strong hold-up play from striker Gary Hooper, the ball found its way to Howson who struck it across the goal and into the corner on the fifth minute.
The Latics responded to going a goal down with some of their own pressure but ended the first half trailing.
The home side had their best chance of the game five minutes after the restart, as James McClean found James Perch in the box but the midfielder's header at goal was well saved by John Ruddy.
Wigan went close to scoring as Marc-Antoine Fortune found himself in some space down the left and fired a shot at Ruddy. The ball was spilled and two Latics attempts from close range were unable to cross the goal line.
Norwich saw out the final few minutes to claim all three points.